A police officer looks at some of the hundreds of ancient artifacts recovered during an operation against looted art, at the Colosseum in Roma Friday, July 16, 2010. The 337 pieces displayed at the ancient Roman arena include vases, bronze tools and marble statues of Venus, some dating as far back as the 8th century B.C. Police said the pieces are worth some 15 million euro (about $20 million) overall. They say the pieces were returned from Switzerland in June after a two-year investigation. AP Photo/Riccardo De Luca.

ROME (AP).- Italian police have recovered hundreds of ancient artifacts in their latest effort to crack down on the looting of art, and have looted art, and they chose a unique setting to display them Friday: the Colosseum.

The 337 pieces displayed in the ancient Roman arena include vases, bronze tools and marble statues of Venus, some dating as far back as the 8th century B.C.

Police said the pieces are worth some euro15 million (about $20 million) overall. They said the pieces were returned from Switzerland in June after a two-year investigation.

Italy has aggressively pursued the return of art it says was illegally looted from its soil and sold to museums or private collections worldwide.

This probe grew out of an investigation into an Italian art dealer later convicted of art trafficking.

The objects were seized in Geneva, part of a massive haul of some 20,000 artworks from all around the world, the art squad of the Carabinieri police said.

The pieces returned to Italy also include "kraters"  huge vases used to mix wine and water  statuettes and drinking cups. Police say the objects were looted mostly from southern Italian regions and, after their spectacular display Friday at the Colosseum, they will return there.

As part of its campaign, Italy has secured the return of dozens of Roman, Greek and Etruscan artifacts in deals with museums including the Met and California's J. Paul Getty Museum. In exchange, Italian art officials have agreed to give the museums long-term loans of equally significant treasures.